Question

: Law of conservation of energy says, ‘ Energy cannot be created or destroyed’
then why do we need to conserve energy?

Answer 1

Answer:

This law, first proposed and tested by Émilie du Châtelet, means that energy can neither be created nor destroyed; rather, it can only be transformed or transferred from one form to another. For instance, chemical energy is converted to kinetic energy when a stick of dynamite explodes......

Answer 2

This is because when we use energy it is transformed into such a form that it is not possible to use it again. So thats the reason why we need to conserve energy.